Pusher for tow lines



y 1962 M. T. SGRICCIA 3,043,236

PUSHER FOR TOW LINES Filed Nov. 10, 1960 2a 27 F 5 25 4 Z3 2! Z9 Z2 6.

35 54 55 as 39 INVENTOR.

3 MAR/0 moms sap/cm ATTORNE Y5 3,043,236 PUSHER FGR TOW LINES Mario Thomas Sgriccia, Detroit, Mich, assignmto Rapistan-Keystone, Inc., Detroit, Micln, a corporation of Michigan Filed Nov. 10, 1960, Ser. No. 68,549

. 6 Claims. (Cl. 104-172) This invention relates to a pusher for tow lines, and more particularly to a pusher for tow lines which releases on overload.

In industrial installations it is common to have an overhead conveyor drive to which is connected pusher mechanism arranged to engage the upright masts of floor trucks for moving them along the floor. One of the problems encountered in this typeof conveying is that the wheels of the truck will engage articles which have inadvertently become placed in the path of the truck and cause the truck to stop. When this occurs the overhead conveyor drive continues to operate and either the mast of the floor truck is broken off 'or damaged or the overhead conveyor drive is broken or damaged.

The present invention overcomes these problems by providing a pusher which releases on overload. If the floor truck stops for any reason, the pusher will release the floor truck mast and the overhead conveyor drive can continue without damage to the floor truck, pusher or overhead conveyor drive.

It is therefore an object of this invention to provide a pusher for tow lines which releases automatically on overload. 1

Another object of this invention is to provide a pusher for tow lines which is constructed of a minimum number of parts and is therefore economical to manufacture and maintain.

Another object of this invention is to provide a pusher for tow lines which has a blocker element to prevent escape of a floor truck mast should it accelerate ahead of the pusher.

These and other objects and advantages of this invention will become apparent upon read ng the specification v in conjunction with the accompanying drawings.

In the drawings:

FIG. 1 is an exploded view of the pusher for tow lines showing the components thereof in perspective.

FIG. 2 is a side elevational view of the pusher for tow lines.

FIG. 3 is a plan view of the pusher for tow lines showing a portion thereof cutaway.

This invention relates to a pusher which is adapted to be secured to an overhead conveyor drive such as a monorail conveyor. The pusher includes a support plate which is adapted to be secured to the overhead conveyor drive. Apair of pusher members are pivotally connected to the support plate and suspended there beneath. The pusher members have guide portions and segments which are offset inwardly from the guide portions forming abutment portions and gate portions. The pusher members are connected to the plate in a manner such that surfaces of the gate portions are normally in contact with each other or in the closed position. The guide portions of the pusher member are adapted to direct the mast of a floor truck into the pusher and guide the mast toa position wherein it engages the abutment portions. Flanges are provided on the gate surfaces and a tension spring connected therebetween.

The spring constantly urges the gate surfaces into contact with each other. Under normal operating conditions the tension spring is sufiicient to hold the gate surfaces in the closed position. I However, if an excessive force is applied to the floor truck mast the spring will yield. The pusher members pivot about a base plate providing for 3,043,236 Farented July 10, 1962 separation of the gate surfaces and allowing passage of the floor truck mast. A blocker member is associated with the guide surfaces and functions to allow the mast of the floor truck to enter; however, if the floor truck accelerates ahead of the overhead conveyor during the conveying operation, the blocker element prevents withdrawal of the mast.

The tow line pusher assembly is designated generally as 10. The assembly. includes the support plate 15, the pusher members 20 and 30, the pivot pins 27 and 37, the blocker 45 and the tension spring 50.

Referring now more specifically to the details of the invention, FIG. 1 shows an exploded view of the tow line pusher assembly 10 and the support plate 15 now to be described.

The support plate 15 is a generally rectangular platelike member. It is provided with a pair of apertures 16 and 17 which extend transversely therethrough. The apertures 16 and 17 are spaced centrally of the longitudinal extent of the member and inwardly from the side edges thereof. These apertures are adapted to receive the pivot pins 37 and 27 respectively for purposes which will be explained more fully hereinafter. The support plate 15 is provided with appropriate fastener means (not shown) for securing the support plate to an overhead conveyor drive or tow line.

A pusher member 20 is positioned beneath the support plate 15 and pivotally connected thereto in a manner which will become more evident subsequently. The pusher plate 20 has a guide surface portion 21 with an exposed end portion 22 which is rolled outwardly. The pusher member 24 also has an offset segment which includes an abutment portion 23 and a gate portion 24. The abutment portion 23 is offset inwardly and is disposed at an oblique angle with respect to the guide portion 20. The gate portion 24 is parallel with the guide portion 20 but is ofiset inwardly therefrom. An L-shaped flange 25 is secured to the end of the gate portion 24 and projects outwardly therefrom. The flange 25 serves as an anchor point for one end of the spring 50 to be explained more fully hereinafter. A sleevelike pivot pin bracket 26 is secured to the outer surface of the abutment portion 23 by means such as weldment. adapted to receive the pivot pin 27.

A stop 29 is secured to the guide portion 20 of the pusher member 21 and is positioned inwardly from the rolled end 22 toward the abutment portion 23. The purpose of the stop 29 will be explained more fully hereinafter. I

A pusher plate or member 30 is also positioned beneath and pivotally connected to the support member 15 adjacent the pusher member 20. The pusher member 30 is a mirror image of the pusher member 20 and has a guide portion 31 with a rolled end 32, an abutment portion 33 and a gate portion 34. The abutment portion 33 andthe gate portion 34 are offset inwardly from the guide portion 31. An L-shaped flange 35 is secured to the gate portion 34 and serves as an anchor point for the other end of the tension spring 50.

A sleevelike pivot pin bracket 36 is secured to the outer surface of the abutment portion 33. It receives the pivot pin 37.

A stop 39 is secured to the inside surface of the guide portion 31 and is spaced inwardly from the rolled end 32 toward the abutment portion 33. .The stop 39 is directly opposite the stop 29 on pusher member 21.

The pusher member 20 is pivotally connected to the support plate 15 by the pivot pin 27. The pivot pin 27 is received within the bracket 26 and secured thereto by any well-known fastening means. The pivot pin 27 projects above the bracket 26 and through the aperture 17 formed in thesupport plate 15. A washerlike collar The pivot pin bracket 26 is means such as welding'or threaded fasteners.

shown in FIGS. 2 and 3 the one edge of the lip '46 abuts the stop'members 2.9 and 39. This prevents counterclockwise rotation ofa blocker 45 from the vertical popin is provided with a cotter pin or lock pin (not shown).

The pusher member 30 is pivotally connected to the support plate by the pivot pin 37. Thepivot pin 37 is received within the bracket 36 and fixed thereto in any well-known manner. The pivot pin 37 projects through the aperture In in the support plate 15 and receives a collar 38 thereover. The top of the pivot pin 37 is provided with a cotter pin or lock pin (not shown) which 7 V maintains the pivot pin in position. 1

A conventional tension spring 56 is connected between the flanges and continuously urging the gate portions 24 and 34 of the pusher members into contact or the closed position. The abutment portions 23 and 33 of the pusher members form a V-shaped work surface against which the mast 55 of a truck 65 abuts.

The guide portions 21 and 31 are provided with apertures adjacent the stop members 29 and 39. These apertures receive a blocker shaft 47 which is journaled therein. These apertures are of suficient size so as to allow the pusher members 29 and 30 to freely pivot about the pivot pins 27 and 37. Washers are positioned on the blocker shaft 47 on either side of the guide portions of the pusher members to facilitate easy rotation of the blocker shaft 47. A cotter pin (not shown) isplaced in the end of the blocker shaft 47 to fix it in position. One end of the blocker shaft 47 is bent to form a handle 48 which can be,

utilized to rotate the blocker shaft 47 to position the blockerimember 55 now to be described. a

The blocker member 45 is a generally rectangular platelike member having a turned over end or lip 46. The lip 46 is secured to the blocker shaft 47 by any conventional sition shown in FIGS. 2 and 3." However, the blocker 45 As best I tions 24 and 34 will pivot in a clockwise and counterclockwise direction respectively and allow passage of the floor truck mast 55 therebetween. After the mast 55 has passed from between the gate surfaces 24 and 34 the spring 50 automatically closes the gate resetting the pusher members 29 and 30 for reception of another floor truck mast. a

The blocker member 45 after being rotated in a clockwise. direction by contact with a floor truck mast and allowing passage of the mast rotates in the counterclockwise direction under the force of gravity. Thus, once the'floor truck mast is within the pusher assembly itcannot inadvertently free itself from the'pusher assembly by accelerating ahead of the overhead conveyor drive since the mast will abut the blocker 45. This arrangement is necessary where the floor over which the floor truck travels is not level and there are downwardly sloping portions. However, if the overhead conveyor drive is stopped for some reason and it is desired torelease the floor truck 6$--from the pusher assembly 'ltl it can be readily accomplished by grasping the handle 48.and rorating the blocker element 45 in the clockwise direction. The mast 55 of the truck can then move under the blocker 45 and be released from the pusher assembly 10.

The pusher assembly disclosed'herein is a highly desirable device since it will release on overload preventing damage to the pusher assembly, overhead conveyor drive and the floor truck. After the pusher has released on overload it automatically resets itself so that it is entirely automatic. mum number of component parts and is therefore economical to manufacture and maintain.

Whileja preferred embodiment of this invention has and. improvements'may be made thereto. Such of these modifications and improvements as incorporate the prinis free to rotate in the clockwise direction.- The blocker M 45 allows passageof the floor truck mast 55 into the pusher assembly 10, but prevents escape of the floor. truck mast should thejtruck accelerate ahead of the overheadconveyor drive. v 7

Operation The overhead conveyor drive travels in the direction of the arrow A shown in FIG. 1. The support plate 15 isfse'cured to the overhead conveyor drive by conventionaI .fastenermeans and is carried therewith; To utilize the ciples of invention are to be considered as included in the hereinafter appended claims unless these claims by their language'expressly state otherwise.

, I claim:

1. A pusher for tow lines comprising; support 'means adapted to be secured to a conveyor drive, a pair of pusherplates pivotally connected .to said support means, said pusher plates having abutment. portions converging to form surfaces adapted to receive the mast of a conveyor. truck, saidpusher plates forming a gate'therebetween adjacent said "abutment surfaces, and resilient pusher assembly 10 a floor truck'fitl h'a'ving an upright mast 55 is positioned in the path of travel of the pusher assembly 10. As the pusher travels the blocker 45v Will eventually come in contact :with the mast 55 of the floor ,truck. This will cause the blocker 45 torotate in a clockwise direction and allow passage of the mastinto the area'between the guide portionszland 31 of. the

pusher members Zll and 30.

fThe rolled out edges 22 and 32 of the pusher members assist in directing the mast of the floor truck to the p0 sition'between'thepusher members. The guide portions 21 and 31 of, the pusher member's. continue to direct the travel of the floor truck mast 55 until it engages the abut 'ment portions 23 and 33 of the'pusher members.

The tension of the spring is such that it closes-the V gate. formed by surfaces on the gate portions 24 and '34 of V the pusher members. The tensionof the spring member 50 is calculated such that the forcesapplied by the floor truck mast to the abutment portions 23 and 33 tending means. continuously urging said gate to a closed position, excess forceon said converging surfaces by said mast causing said gate to open and release said mast to prevent damage thereto. t U a r V 2. A pusher for an overhead. conveyor drive comprising; asupport plate adapted to be secured to an overhead conveyor drive,- a first pusher member pivotally connected tosaid support plate, said first pusher member having asegment thereof ofiset inwardly'to form an abutment portion and a gate portion, a secondpusher member pivotally connected to said support plate. and having a segment thereof ofiiset inwardly to form an abutment portion and a gate portion, flange members associated with said gate portions and spring means to urge said gate portions into contact with each other to form a closed'gate,

to open the gate under ordinary'load-conditions is less than the'force applied by the spring tending to close the 'lgate. Therefore, under normal operating conditionsithe gate remains'close'd and the pushermembers assume the position shown inFIG. 3. a

However, should'the mast 55' apply an excessive force to the abutment surfaces 23 and 33, due for instanceto the fioorjtruck engaging an obstaclein its patl n'the tension of the s'p'ring'5tl will'be overcome and the gate porsaid abutment portions being convergent with respect to each other and adapted to ,engage'the mast of a floortruck for movement thereof, said first and second pusher members, pivoting to open said gate when an excessive force is applied to said mast and closing automatically bytheaction of said' spring means after release of said mast. 1

.3; A pusher for an'overhead conveyor drive as in claim 2 wherein said first and secondpusher members have guide portions for directingsaid mast into engagement with said abutment surfaces.

4. A pusher for an overhead'conveyor drive as in claim: "3 wherein blocker means is connected to said guidesur- The device is constructed of a minifaces to admit entry of said mast to said guide surfaces but prevent inadvertent withdrawal therefrom upon acceleration of said mast ahead of said conveyor drive.

5. A pusher for an overhead conveyor drive comprising; support means adapted to be secured to an overhead conveyor, generally convergent pusher means movably secured to said support means, said pusher means adapted to receive the mast of a floor-truck, said pusher means having gate means resiliently urged to the closed position, said gate means opening to release said mast on overload.

6. A pusher for an overhead conveyor drive comprising; a support plate adapted to be secured to an overhead conveyor drive, a first pusher member pivotally connected to said support plate, said first pusher member having a guide portion and a segment thereof oifset inwardly to form an abutment portion and a gate portion, a second pusher member pivotally connected to said support plate and having a guide portion and a segment thereof ofiset inwardly to form an abutment portion and a gate portion, flange members associated with said gate portions and spring means positioned therebetween to urge said gate portions into contact with each other to form a closed gate, said abutment portions being generally convergent and adapted to engage the mast of a floortruck for movement thereof, said first and second pusher members pivoting to open said gate when an excessive force is applied to said mast and closing automatically after release of said mast, blocker means pivotally mounted on said guide surfaces to admit entry of said mast, and stop means secured to said guide portions and engageable by said blocker means to limit pivotal movement thereof in a direction to prevent withdrawal of said mast from said pusher upon acceleration of said mast ahead of said conveyor drive.

References Cited in the file of this patent UNITED STATES PATENTS 797,610 Schaefer Aug. 22, 1905 2,161,388 Rosenthal June 6, 1939 2,572,011 Cohen et a1 Oct. 23, 1951 2,619,370 Leger Nov. 25, 1952. 2,885,969 Kay et a1. May '12, 1959 2,956,514 Bishop Oct. 18, 1960 

